A brush direct current motor includes a stator and a rotor rotatably mounted to the stator. The rotor includes a shaft, a commutator fixed to the shaft, a rotor core, and rotor windings wound around the rotor core and electrically connected with segments of the commutator. The motor further includes a brush assembly. The brush assembly includes brushes electrically connected with the commutator segments. When the rotor operates, the rotor rotates at high speed relative to the stator, frequent altering of polarities of the rotor windings generates high frequency signals which are radiated from the motor and, as a result, the motor causes an electromagnetic interference (EMI).